As a general rule, you should always backup your site before any change, and a migration is not an exception. Having said this, we perform the migration on our own servers and, unless you say so, we will not modify your current database but will just send you the generated SQL file. Then, it’s up to you to decide whether to backup the site before importing such file (again, our recommendation is to do so!).
Posted in: Migration process Do I need to backup the website to be migrated?